As a fuel filler structure for fueling the fuel tank of a vehicle or the like, there is a fuel filler structure configured in such a way that the fuel fill inlet, into which the fuel nozzle is inserted, can be opened and closed by an opening-and-closing valve such as a flapper valve. For example, in patent document 1 (JP-A No. 2008-49952), there is described a structure configured in such a way that an inclined surface leading from a lead-in opening to an open portion is formed in an opening forming member so as to guide the fuel nozzle to the open portion.
However, there are fuel nozzles that have a large diameter portion in the middle of their lengthwise direction, such as fuel nozzles with a structure where a helical spring is attached to the outer periphery of a tubular fuel nozzle body. It is necessary for the smallest diameter section of the inner diameter of the inclined surface (guide surface) to be given a size considering the large diameter section (spring section) in the middle of the fuel nozzle. However, when the smallest diameter section of the inclined surface is made larger, it becomes difficult for the fuel filler structure to highly demonstrate the action of guiding the distal end of the fuel nozzle to the fuel fill inlet.